You might know that your smartphone is protected by Gorilla Glass. But how did Gorilla Glass come to be every phone's bodyguard?

ITworld|October 1, 2012

If this post does nothing else for you, you will have seen someone play Fruit Ninjausing an actual knife. For all your worries about every possible scratch or dent on your phone, this guy is straight cutting his phone with a knife, making a mockery of your anxiety.

Gorilla Glass and its sequel are perhaps the most prominent component of all the iPhones released so far. Gorilla Glass 2 is in HP’s new ElitePad Windows 8 tablet, in the new Kindle Fires, and in just about every new mobile device that cares about its user being confident in its strength. Yet our sum knowledge, from the consumer standpoint, comes down to this: it is tough, it is made somewhere near Rochester, NY, and ... hey, it’s really tough and cool stuff.

But let’s dig in an learn a bit more about Gorilla Glass, in appropriately mobile-sized chunks.

The 1960s protoypes could have killed your uncle: It’s part of the Gorilla Glass lore that prototypes of the scratch-resistant glass were developed as early as 1962. But the specifics of the failed 1962-1971 run of “Chemcor” were recently detailed by Wired:

Some companies did place small orders for products like safety eyeglasses. But these were recalled for fear of the potentially explosive way the glass could break. Chemcor seemed like it would make a good car windshield too, and while it did show up in a handful of Javelins, made by American Motors, most manufacturers weren’t convinced that paying more for the new muscle glass was worth it ... It didn’t help that crash tests found that “head deceleration was significantly higher” on the windshields—the Chemcor might remain intact, but human skulls would not.

It’s not keys, it’s pocket sand that scratches your phone: Per Lifehacker’s summation of a very smart XDA video test, it’s the little things that will put all those resale-ruining scratches into your smartphone screen, not the big stuff you’re worried about: keys, ID lanyards, and the like. Not to say that your keys and jeans buttons can’t scratch your phone, but small particles, put in direct and tumbling contact with your phone, are at least as dangerous. Use a screen protector if you’re looking to keep your screen in mint condition.

Aluminosilicate compositions like Gorilla Glass contain silicon dioxide, aluminum, magnesium, and sodium. When the glass is dipped in a hot bath of molten potassium salt, it heats up and expands. Both sodium and potassium are in the same column on the periodic table of elements, which means they behave similarly. The heat from the bath increases the migration of the sodium ions out of the glass, and the similar potassium ions easily float in and take their place. But because potassium ions are larger than sodium, they get packed into the space more tightly. (Imagine taking a garage full of Fiat 500s and replacing most of them with Chevy Suburbans.) As the glass cools, they get squeezed together in this now-cramped space, and a layer of compressive stress on the surface of the glass is formed. ... (T)he “stuffing” or “crowding” effect in chemically strengthened glass results in higher surface compression (making it up to four times as strong), and it can be done to glass of any thickness or shape.

Gorilla Glass has at least two cousins, “Willow” and “Lotus”: Lotus Glass is a partnership between Corning and Samsung to create durable glass for next-generation organic light-emitting diode (OLED) displays. That’s playing the long game, as more monitors and phones move toward the lower-power, constantly evolving OLED field. Then there’s Willow Glass, which, while something of a different product, definitely owes its existence and touch-sensitive focus to the success of Corning’s collaboration with Apple on the big Gorilla Glass bake-off.